{
\def\sym#1{\ifmmode^{#1}\else\(^{#1}\)\fi}
\begin{tabular}{l*{4}{c}}
\hline\hline
                    &\multicolumn{2}{c}{\% Republicans (Hersh)} &\multicolumn{2}{c}{\% Donation to Republicans (DIME)}\\
                    &\multicolumn{1}{c}{(1)}         &\multicolumn{1}{c}{(2)}         &\multicolumn{1}{c}{(3)}         &\multicolumn{1}{c}{(4)}         \\
                    &        none         &           B         &           C         &           D         \\
                    &        none         &        none         &        none         &        none         \\
\hline
Single Practice     &       0.052\sym{***}&       0.025\sym{**} &       0.061\sym{***}&       0.036\sym{***}\\
                    &     (0.009)         &     (0.009)         &     (0.010)         &     (0.009)         \\
[1em]
Constant            &       0.444\sym{***}&       0.404\sym{***}&       0.282\sym{***}&       0.287\sym{***}\\
                    &     (0.006)         &     (0.106)         &     (0.004)         &     (0.004)         \\
\hline
Controls            &                     &                     &                     &                     \\
Observations        &       13678         &       13651         &       12830         &       12830         \\
R-squared           &        0.00         &        0.05         &        0.00         &        0.15         \\
\hline\hline
\multicolumn{5}{l}{\footnotesize \sym{*} \(p<0.05\), \sym{**} \(p<0.01\), \sym{***} \(p<0.001\)}\\
\end{tabular}
}
